Do you use ASSM (Automatic Segment Space Management)?

From: ca111026 <>
Date: Mon, 3 Aug 2009 17:07:59 -0700 (PDT)
Message-ID: <>

Do you use ASSM (Automatic Segment Space Management)? This feature was introduced in 9.2. The benefits are unclear - have anyone seen test results proving that in real-life situation ASSM produces improvements?
At the same time ASSM has so many bugs: slow performance, spin/hang, excessive space usage, space leaks, etc. Just search Metalink for ASSM. Almost all ASSM-related bugs are "private", i.e. no additional information is available.

For example:

Bug 7575925 – ASSM blocks may be marked with wrong “freeness” (private bug)
Affected version:
Fixed in:, 11.2 (Future Release)

Bug 5728380 – DML may spin searching for space in ASSM (private bug) Affected versions:,

We had several instances where Apps Support would run large uncomitted DELETE (in different apps) and performance of single-row INSERT would deteriorate dramatically: from 10 buffer gets per INSERT to 100,000. Received on Mon Aug 03 2009 - 19:07:59 CDT

Original text of this message